Originally Posted by fordman75

That's a dipstick tube! From the length I'd say that oil pan was replaced with one from a van ( from the late 70's- 82 or 83 ) !

It should just screw into the side of the oil pan. Put a vacuum port cap over the tube. And when you do your next oil change, drain your oil and then unscrew the tube from your oil pan. Then take the tube to your local hardware store or auto parts place and find a plug with the correct threads ( No, do not drive the truck with no oil or the tube not installed without the plug installed! ) . Ad some thread sealant to the plug, install it and no more ugly tube in your way!

To be sure, can you get a picture of the oil pan where the tube goes in?